Fuel Pump B Control Circuit / Open
The controller cannot drive the secondary fuel pump (B). Common on dual-tank trucks, GDI lift-pump systems, or alt-fuel installations — fault stops fuel delivery from this stage.
Affected components
- Fuel pump b
- Fuel pump relay b
- Wiring harness
Common causes
- High likelihood: Open pump motor winding
- Medium likelihood: Failed pump relay
Possible symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.